Deep Inspiration breath Hold facilitates surgical cavity registration on cone beam imaging for Partial breast irradiation.

Images from 21 patients, with 15 CBCT each, were evaluated by 6 radiation therapists, generating 4,015 evaluation points. Statistically significant improvements were observed in CVS and image quality (p < 0.001) with DIBH. Also, the rate of surgical cavity identification increased to 76 % with DIBH compared to 56 % without (p < 0.001). DIBH significantly reduced the inter-observer variability in registration shift corrections (p < 0.001) CONCLUSION: Utilizing DIBH for motion control improves both the image quality and the surgical cavity identification. This results in a decrease in registration variability, which is important for APBI accuracy.